Cardiac variation in different strains

In the last decade genetic diversity within inbred mouse strains was often recognized. However, the need for comparability and standardization of cardiac phenotyping methods is strong. Furthermore large scale analyses of mutants need standardized high-throughput methods to be able to discriminate healthy from ill. The scientists around Kristin Moreth from the Insitute of Experimental Genetics in the Helmholtz Center Munich developed a protocol for non-invasive, reliable, easy and fast to perform echocardiography and electrocardiography on awake mice (awake ECHO and ECG) that can be used to analyze the murine cardiovascular system in large-scale-analyses. The four inbred mouse strains C57BL/6N, C57BL/6J, C3HeB/FeJ and 129P2/OlaHsd were used in this study. The results provide evidence for physiological divergence of the cardiovascular system of the four tested strains and define the expected normal values.

Interestingly the analysis showed clearly that C57BL/6N hearts reveal features of heart failure such as hypertrophy and reduced contractile function as indicated by a higher muscle mass and a poorer left ventricular function. The results highlight the challenges that need to be accepted because of the strain-dependent differences in physiological function. Nevertheless, the authors state, the complex variation can help to get further insights into disease processes.